綠竹 BoMSP41 與其他生物分子交互作用之探討

綠竹筍出土後生長快速的現象早有記錄，但至今綠竹生長相關的調控機制尚未被建立。BoMSP41 (Bambusa oldhamii monocot specific protein-41) 為一個於綠竹筍快速生長的節間中表現量大幅提升的基因，但對其功能尚不清楚。而 BoMSP41 蛋白質被預期是無穩定構形蛋白質（Intrinsically disorder protein, IDP），可能會透過與不同生物分子結合後，形成穩定的構形參與不同的生理反應。透過酵母菌雙雜合系統（Yeast two hybrid, Y2H）於綠竹筍 cDNA library 進行篩選可能與 BoMSP41 有交互作用之蛋白質，然而，篩選到的 185 株候選菌株於後續酵母菌雜交驗證中，皆未有對 BoMSP41 有專一性交互作用的候選目標。另一方面，於綠竹未展開葉跟阿拉伯芥之原生質體中，利用短暫性表現 GFP-BoMSP41 融合蛋白質去分析 BoMSP41 的細胞內定位，可於阿拉伯芥的原生質體中觀察到 BoMSP41 位於細胞膜；而於綠竹原生質體中則是觀察到 BoMSP41 存在於細胞質、細胞膜與葉綠體，因觀察到 BoMSP41 位於細胞膜上，推測 BoMSP41 可能會與膜蛋白質產生交互作用或是 BoMSP41 可能屬於單側嵌膜蛋白質 (integral monotopic protein)。此外，BoMSP41 會與染色質產生交互作用，雖目前無法確認是否為直接與 DNA 有交互作用。BoMSP41 出現於多樣性的胞器之中，推測 BoMSP41 可能涉及多種不同的生理反應之中。

關鍵字

綠竹； BoMSP41 ；無穩定構形蛋白質；膜蛋白質

並列摘要

The fast-growing feature of bamboo shoots has been recorded, but the related regulatory mechanism has not been elucidated. BoMSP41 (Bambusa oldhamii monocot specific protein- 41) is an unknown function gene that is highly up-regulated in rapidly elongating bamboo shoots. The protein encoded by this gene was suggested to be an intrinsically disorder protein (IDP), which might interact with other biomolecules to perform its function. To identify BoMSP41-interacting proteins, yeast two-hybrid screening was performed with a bamboo shoots cDNA library. Although 185 candidates were obtained, none of them specifically interacted with BoMSP41 after confirmation. Transient expression of GFP-BoMSP41 fusion proteins in protoplasts isolated from Arabidopsis leaves and bamboo unexpanded leaves showed that BoMSP41 was localized in the plasma membrane of Arabidopsis protoplasts, and in the cytoplasm, plasma membrane and chloroplasts of bamboo protoplasts. Localization of BoMSP41 in plasma membrane suggested that the protein may interact with membrane proteins or it is a kind of integral monotopic protein. In addition, BoMSP41 was found to interact with chromatin; however, whether it directly interact with DNA or not remains unknown. Presence of BoMSP41 in various cellular compartments suggested that this protein participate in multiple pathways.